In the broken case no framebuffer is available before accelerated driver loads. The mode detection happens way before simpledrm can do anything so I wonder how it would be affected. ... unless there is a condition to enable more modes that depends on vesafb and is not selected with simpledrm. FWIW here is a 5.15.12 that should match the working one with simpledrm enabled: https://build.opensuse.org/project/monitor/home:michals:kernel-test